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Revision History for A050150

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Showing entries 1-10 | older changes

A050150

Odd numbers with prime number of divisors.
(history; published version)

#27 by Michel Marcus at Sun Jul 14 05:06:32 EDT 2024

STATUS

reviewed

approved

#26 by Joerg Arndt at Sun Jul 14 04:09:30 EDT 2024

STATUS

proposed

reviewed

#25 by Jason Yuen at Sun Jul 14 04:02:50 EDT 2024

STATUS

editing

proposed

#24 by Jason Yuen at Sun Jul 14 04:02:42 EDT 2024

FORMULA

A010051(a100995A100995(a(n)) + 1) = 1. - Reinhard Zumkeller, Aug 16 2013

STATUS

approved

editing

#23 by N. J. A. Sloane at Tue Jul 05 23:14:48 EDT 2022

STATUS

proposed

approved

#22 by Michael S. Branicky at Tue Jul 05 15:16:46 EDT 2022

STATUS

editing

proposed

#21 by Michael S. Branicky at Tue Jul 05 15:16:44 EDT 2022

PROG

(Python)

from sympy import divisor_count, isprime

def ok(n): return n and n%2 and isprime(divisor_count(n))

print([k for k in range(250) if ok(k)]) # Michael S. Branicky, Jul 05 2022

STATUS

approved

editing

#20 by N. J. A. Sloane at Fri Dec 15 17:34:50 EST 2017

AUTHOR

_Jason Earls (zevi_35711(AT)yahoo.com), _, Jul 04 2001

Discussion

Fri Dec 15

17:34

OEIS Server: https://oeis.org/edit/global/2722

#19 by N. J. A. Sloane at Sat Feb 14 21:31:41 EST 2015

STATUS

proposed

approved

#18 by Jon E. Schoenfield at Sat Feb 14 21:25:37 EST 2015

STATUS

editing

proposed